When drugs of abuse are smoked, volatile components and pyrolysis material escape into the atmosphere. Depending on the local environment, bystanders may be exposed to the drug by passive inhalation of the contaminated air. Present studies are underway to develop means of heating drugs of abuse in a controlled environment and measuring air levels of drug in order to evaluate this potential hazard. Initially, free-base cocaine "crack" and methamphetamine "ice" will be evaluated for potential passive inhalation exposure. Unknowing drug exposure could be dangerous to unsuspecting bystanders, particularly to small children. These studies will establish limits of exposure to volatile components of drugs under controlled conditions.